The normal pulse rate of a 13-year-old is between 70 and 100 beats per minute. As part of a health program, the medical staff at Grant Middle School measured the resting pulse rate of 12 randomly selected students in grades 7 and 8. The box plot shows the data for each group. Which statement correctly compares the data sets?

* A. The difference of the medians is about half of the interquartile range of either data set.
* B. The difference of the medians is about 2 times the interquartile range of either data set.
* C. The difference of the medians is about one-fourth of the interquartile range of either data set.
* D. The difference of the medians is about 4 times the interquartile range of either data set.